Belt conveyor devices are used as item transportation means in various industrial fields such as steel, coal, and cement. As many belt conveyor devices are required to be of very long distance nowadays, there is strong demand for conveyor belts having higher energy saving performance.
To satisfy such demand, various conveyor belt rubber compositions have been used conventionally. For example, Patent Literature (PTL) 1 discloses the following conveyor belt rubber composition. Natural rubber (NB) and polybutadiene rubber (BR) are used in combination as the rubber component, to which carbon black having a predetermined nitrogen adsorption specific surface area and dibutylphthalate oil absorption is added, thus reducing power consumption while maintaining favorable basic physical properties as a conveyor belt.